Methods and devices for diagnostic and therapeutic interventions in the peritoneal cavity

ABSTRACT

A novel approach to diagnostic and therapeutic interventions in the peritoneal cavity is described. More specifically, a technique for accessing the peritoneal cavity via the wall of the digestive tract is provided so that examination of and/or a surgical procedure in the peritoneal cavity can be conducted via the wall of the digestive tract with the use of a flexible endoscope. As presently proposed, the technique is particularly adapted to transgastric peritoneoscopy. However, access in addition or in the alternative through the intestinal wall is contemplated and described as well. Transgastric and/or transintestinal peritoneoscopy will have an excellent cosmetic result as there are no incisions in the abdominal wall and no potential for visible post-surgical scars or hernias.

This application claims the benefit of U.S. Provisional Application Ser.No. 60/191,764, which was filed Mar. 24, 2000, the disclosure of whichis incorporated herein by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a procedure for accessing and examiningand/or conducting surgical procedures in a body cavity, such as theperitoneal cavity, and instruments adapted therefor.

2. Description of the Related Art

The traditional approach to the peritoneal cavity is by trans-abdominalwall incision. More recently, the less invasive laparoscopic surgicaltechnique has been used to access and examine the peritoneal cavity.Laparoscopy is currently performed via small incisions made through theanterior abdominal wall. Via these incisions, a rigid laparoscope isintroduced, as are various microsurgical instruments if a procedure isperformed within the peritoneal cavity. Laparoscopy is therefore asurgical procedure and carries the risk of infection of the skinincisions and possible development of post-operative hernias, and/orscars which may create cosmetic defects.

BRIEF SUMMARY OF THE INVENTION

We have developed a novel approach to diagnostic and therapeuticinterventions in the peritoneal cavity. More specifically, we havedeveloped a technique for accessing the peritoneal cavity via the wallof the digestive tract so that examination of and/or a surgicalprocedure in the peritoneal cavity can be conducted via the wall of thedigestive tract with the use of a flexible endoscope. As presentlyproposed, the technique is particularly adapted to transgastricperitoneoscopy. However, access in addition or in the alternativethrough another wall of the digestive tract, such as the intestinal wallor the esophageal wall, is contemplated and described generally as well.Transgastric and/or transintestinal peritoneoscopy will have anexcellent cosmetic result as there are no incisions in the abdominalwall and no potential for visible post-surgical scars or hernias.

BRIEF DESCRIPTION OF THE DRAWINGS

These, as well as other objects and advantages of this invention, willbe more completely understood and appreciated by careful study of thefollowing more detailed description of the presently preferred exemplaryembodiments of the invention taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is an illustration of an overtube according to an embodiment ofthe invention, with balloons deflated;

FIG. 2 is a view similar to FIG. 1 with the balloons inflated;

FIG. 3 is an illustration of a dilating needle-knife device according toan embodiment of the invention, with balloon deflated and needleretracted;

FIG. 4 is an enlarged view of the tip of the needle-knife device of FIG.3 with the needle extended;

FIG. 5 is view of the needle-knife device of FIG. 3, with a guidewiresubstituted from the needle-knife wire and with the balloon inflated;

FIG. 6 is a schematic view showing the overtube with endoscope disposedtherewithin located to a target portion of the stomach wall via theesophagus;

FIG. 7 is an enlarged view showing the needle-knife device disposed forincising the stomach wall to provide access to the peritoneal cavity;

FIG. 8 is an enlarged view showing the needle-knife device displacedthrough the incision in the stomach wall, with needle retracted;

FIG. 9 is an enlarged view of the needle-knife device disposed throughthe incision in the stomach wall, with a guide wire disposedtherethrough and with balloon inflated;

FIG. 10 is an enlarged view showing the overtube disposed through thestomach wall with one of the anchoring balloons inflated to limitovertube insertion;

FIG. 11 is an enlarged view showing the overtube disposed through thestomach wall with both of the anchoring balloons inflated for anchoringthe overtube to the stomach wail, thereby establishing a passage intothe peritoneal cavity;

FIG. 12 is a perspective view showing the surface of the stomach withthe overtube anchored thereto and an endoscope projecting from theovertube for visualizing, examining and/or conducting a surgicalprocedure in the peritoneal cavity;

FIG. 13 is a schematic view showing the endoscope ready to apply clipfixing devices to close the incision in the gastric wall at theconclusion of the procedure;

FIG. 14 is a schematic view showing a clip fixing device engaging a sideof the incision as a step in the clipping process;

FIG. 15 is a view similar to FIG. 14 showing the clip fixing deviceengaging both sides of the incision, prior to closing the clip;

FIG. 16 is a schematic view showing the clip fixing device closed toclose a part of the incision; and

FIG. 17 is a schematic view showing clip fixing devices applied side byside to close the incision in accordance with an exemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

We have developed a new approach for the examination of the peritonealcavity that uses a flexible endoscope and a specially adapted sterileovertube with anchoring balloons. The endoscopic procedure of theinvention proposes to access the peritoneal cavity for examinationand/or for the conduct of select surgical procedures via an incisionthrough a wall of the digestive tract. The invention is described ingreater detail herein below with reference in particular to peritonealaccess through the stomach wall via the esophagus. However, as will beunderstood by those skilled in this art, using our approach, theperitoneal cavity can be accessed in addition or in the alternative viathe intestinal wall and, depending upon the locus of the target accesspoint(s), an esophageal approach and/or a colorectal approach can beadopted. In addition, the thoracic cavity may be approached through theesophagus or stomach.

This novel endoscopic procedure will be described herein below withreference to instruments and devices, some of which have been developedspecifically for the implementation of this procedure. While some of thedevices described herein are particularly adapted to this procedure, itis to be understood that commercial available devices may also be usedto advantage to implement the process of the invention. Therefore, theendoscopic procedure of the invention is not to be limited to the use ofa particular instruments described herein. The provision and use ofdevices specially adapted to this procedure may, however, facilitate itssuccessful implementation. As will also be appreciated and understoodfrom the disclosure to follow, the instruments developed for theimplementation of this procedure may also be used to advantage in theconduct of other medical procedures. Thus, those novel instruments arenot to be construed as limited to the uses therefor described hereinwith reference to transgastric peritoneoscopy.

As noted above, the invention provides a novel approach to theperitoneal cavity via the digestive tract. A transgastric approach isdescribed in particular herein below, by way of example. Those skilledin the art will appreciate, however, how the techniques described hereincan be applied to peritoneal access through other portions of thedigestive tract and/or achieved via a colorectal approach. Accordingly adetailed description of such alternatives is omitted. Nevertheless, theinvention is not to be limited to the presently proposed and preferredtransgastric approach.

To access and examine the peritoneal cavity via the digestive tract inaccordance with the present invention, a passage for the sterileinsertion of an endoscope and/or various surgical instruments must beprovided that isolates the peritoneal cavity from the interior of thedigestive tract, such as the gastric cavity. Such a sterile pathway isprovided in the presently preferred embodiment of the invention byproviding a special, sterile overtube 10 having a conduit 12 that issized to receive an endoscope therethrough and is flexible so as to becapable of flexing with the endoscope to navigate the digestive tractand be conducted and directed to a target access point on, e.g., thestomach wall. Typical endoscopes have an outer diameter on the order ofabout 10-15 mm. Accordingly, the overtube 10 preferably has in interiorpassage for the endoscope having a diameter of at least about 10 mm andpreferably in the range of about 10-20 mm.

To allow visualization of the vicinity of the distal end of the overtubefrom within the overtube 10, via the endoscope, during the insertion ofthe overtube, incision of the stomach wall, and anchoring of theovertube, as described in greater detail herein below, in the presentlypreferred embodiment of the invention at least a distal portion 20 ofthe overtube 10 is formed from a transparent material. For ease ofmanufacture, the entire overtube conduit 12 may be advantageously formedfrom a transparent material.

The proximal end of the overtube 10 is provided with a valve housing 14that includes a chamber 16 through which the endoscope passes into thelumen of the overtube conduit. The housing is configured to providestructural support for a valve/seal mechanism shown generally at 18. Itis the function of the seal to prevent the escape of pressurized fluidthrough the overtube conduit 12 following insufflation to expand theperitoneal cavity for adequate examination. Any valve structure ormechanism now known or later developed to effect a seal about anendoscope or other instrument inserted through an access port tominimize escape of pressurized fluid can be provided to advantage at theproximal end of the overtube 10. In an exemplary embodiment, a suitablevalve includes an aperture or septum seal having an aperture that allowsit to receive and closely engage the outer surface of an endoscopeinserted therethrough to form an airtight seal around the endoscope inoperative use. This valve is formed from elastomeric material so thatthe aperture is biased to seal against the outer surface of theendoscope. In order to avoid significant friction forces, the apertureis preferably sized to a diameter slightly less then the outer diameterof the endoscope to be inserted therethrough. To accommodate a varietyof instruments, however, the size of the aperture is preferablyexpandable without inducing substantial frictional forces to accommodatethe various instrument sizes. Although a valve having a expandableaperture has been mentioned in particular above, it is to be understoodthat a zero closure valve may be provided in stead of or in addition tosuch an apertured sealing member.

The distal end 20 of the overtube is adapted to be anchored to the wallof, e.g., the stomach, at least during the peritoneoscopy and associatedsurgical procedure(s), if any, to provide a continuous path to and intothe peritoneal cavity and to isolate the peritoneum from the gastriccavity. Such an anchoring and sealing function is provided in accordancewith an exemplary embodiment of the invention by providing a pair ofanchoring cuffs or balloons 22, 24 adjacent the distal end of theovertube. To selectively inflate and deflate the balloons, an inflationpassage (not shown) for each balloon is defined longitudinally of theovertube, terminating proximally in respective inflation lines 26, 28and inflation ports 30, 32. The inflation passages can be defined withinthe overtube wall or so as to extend along the interior or exteriorsurface of the overtube in a known manner.

Thus, as described in greater detail herein below, the distal end of theovertube is inserted through an incision formed in the gastric wall andthe anchoring balloons provided adjacent the distal end are inflated,with one inside the peritoneal cavity and the other one inside thestomach. The more proximal balloon 22 may be inflated first to precludeover insertion of the overtube at the outset. The inflated balloonsanchor the distal end 20 of the overtube 10 to the gastric wall toprevent the overtube from migrating further into the peritoneal cavityor back into the stomach and isolate the peritoneal cavity from thegastric cavity. The overtube thus disposed advantageously provides aconduit for manipulations inside the peritoneal cavity. Accordingly, aflexible endoscope can be advanced through the overtube into theperitoneal cavity for diagnostic examination and/or surgicalmanipulations. After the procedure has been completed, the anchoringballoons are deflated and the overtube and endoscope pull back into thestomach. As described in greater detail herein below, the remainingincision in the gastric wall is then closed. Most preferably, theincision in the gastric wall is closed with endoscopic clips deliveredvia the endoscope. In the alternative, sutures or other ligatures can beapplied to close the incision, again most preferably using suitablemicrodevices fed through lumens therefor in the endoscope.

Referring to FIG. 6, a portion of the digestive tract including thedistal end of the esophagus 34, the stomach 36, and the duodenum 38 areschematically shown as is an overtube 10 that has been fed through theesophagus 34 to terminate distally adjacent a target portion of thegastric wall. The overtube is desirably guided and directed into andwithin the stomach, in this example, or other segment of the digestivetract, with the aid of an endoscope 40 coaxially disposed therewithin.

As suggested above, to access the peritoneal cavity via the digestivetract, it is necessary to penetrate the wall of, e.g., the stomach.Desirably, the penetrating incision of the wall is made endoscopicallyby passing a suitable instrument through an accessory channel of theendoscope so that the procedure can be observed through the endoscope.Furthermore, desirably the incision is made as small as possible tofacilitate the closure of the incision at the conclusion of theprocedure, and is made in such a manner as to minimize bleeding.

In view of the objective of providing as small an incision as possibleand the need to accommodate the overtube, an instrument for dilating theincision is preferably provided. The incising and dilating steps orfunctions may be provided by separate instruments. However, tofacilitate the procedure, we have developed a combined incising anddilating device 42 that can be used to substantial advantage in thepractice of the invention. The conduct of the incising and dilatingprocesses using independent instruments and using our novel incising anddilating instrument will each be described herein below.

A dilating needle-knife device 42 for sequential incision and dilationto provide access through the wall of an organ or body passage isillustrated by way of example in FIGS. 3-5 and 7-9, in particular. Thedilating needle-knife device 42 we have provided includes an elongatedconduit 44 having proximal and distal ends. A needle-knife actuator 46is mounted to the proximal end and a wire or needle-knife 48 extendstherefrom longitudinally of the device to terminate adjacent the distalend of the elongate conduit. The needle-knife actuator 46 includes aslide trigger 50 that is secured to the proximal end of the needle-knifewire for selectively projecting the needle-knife 48 as shown in FIG. 4and retracting the needle-knife as shown in, e.g., FIG. 3. An electricalcoupler 52 is provided on the needle-knife actuator 46, morespecifically on the trigger 50, for electrically coupling theneedle-knife wire 48 to a current source (not shown). Electrification ofthe needle-knife can be selectively accomplished by a foot pedal switchor the like (not shown), in a conventional manner.

An elongated balloon structure 54 is suitably formed on or mounted tothe conduit 44 adjacent the distal end of the device and an inflationpassage for the balloon 54 is defined longitudinally of the conduit andterminates proximally in an inflation port 56. The dilating needle-knifedevice 42 is adapted to be passed through the accessory channel of anendoscope. Thus, desirably, the conduit for the needle-knife wire 48 andthe inflation passage for the balloon 54 define a profile that can beslidably accommodated in a standard endoscope accessory channel. Such alow profile dual passage conduit can be defined by concentric passagesor side by side passages.

As explained in greater detail below, once an incision has been made bythe needle-knife 48, care must be taken to avoid loss of the point orshort line of incision during subsequent manipulation of theinstruments. Accordingly, the dilating needle-knife device 42 is adaptedfor the selective removal of the needle-knife wire 48 and replacementthereof with a fine guide wire 58. Accordingly, once the incision hasbeen made, the needle-knife 48 is retracted and the dilatingneedle-knife device 42 is advanced proximally so as to be disposedthrough the just formed incision. The needle-knife actuator 46 is thendisengaged, i.e. unthreaded, from the proximal end 60 of theneedle-knife conduit 44 and the needle-knife wire 48 withdrawn so that afind guide wire 58 can be accommodated in the conduit 44 of theneedle-knife device 42. The guide wire 58 is advanced so as to protrudefrom the distal end of the needle-knife conduit 42, as shown in FIG. 5.Care is desirably taken to avoid excessive overfeed of the guide wire.To that end, the procedure may be fluoroscopically monitored and/orindicia may be provided on the guide wire so as to communicate to thesurgeon the relative disposition of the guide wire 58 and theneedle-knife conduit 44.

As noted above, the incision is desirably dilated to accommodate, e.g.,the overtube 10. Accordingly, the dilating needle-knife device of theinvention provides an elongated balloon 54 that may be selectivelyinflated while the needle-knife conduit is disposed to traverse theincision, thereby to dilate the same. In the illustrated embodiment, thedilating balloon 54 has a relatively low profile so as to avoid overdilation and the potential for tearing of the organ wall. The balloon iselongated in the illustrated embodiment so that the disposition of theneedle-knife conduit 44 relative to the incision is less critical. Inthat regard, it is to be recalled that during the procedure, theincising and dilating procedure are observed through the endoscope 40disposed in the overtube 10. However, during the dilating process, thevisualization is limited to the gastric cavity side of the incision. Theelongated balloon 54 also ensures that there will be uniform dilation ofthe stomach wall which may vary in thickness from patient to patient andfrom one locus to another. The length of the balloon is substantiallygreater than its diameter following inflation. More specifically, theballoon length is at least about twice the inflated diameter and morepreferably about three to five times the inflated diameter, as shown inFIG. 5.

While the dilating needle-knife device 42 shown in FIG. 3 et seq hasbeen described above in particular with reference to the process ofincising the gastric wall to provide access to the peritoneal cavity andthe dilation of the just incised wall, the dilating needle-knife devicemay be used in connection with a variety of other endoscopic procedures,including subsequent diagnostic and/or surgical procedures within theperitoneal cavity during transgastric peritoneoscopy. Indeed, theability to sequentially incise and dilate using a single instrument toallow access to and selective passage into various organs and bodypassages minimizes the need to repeatedly exchange instruments throughthe accessory channel of the endoscope, thus reducing the steps of theprocedure and minimizing the chance that the incision point will belost. This potentially reduces the duration, cost and risks of theprocedure.

As noted above, although the dilating needle-knife device we havedeveloped can be used to substantial advantage according to theinvention, as noted above, independent instruments may be sequentiallyused to accomplish the incising and dilating steps of the process. Thus,instead of the dilating needle-knife device described herein above, aconventional needle-knife can be fed through the accessory channel ofthe endoscope to the site to be incised, foot pedal or otherwiseactuated to suitably heat the needle-knife which is then disposedrelative to the target wall to form the desired incision. To locate andmaintain the patency of the thus formed incision, the needle-knife isadvanced through the incision. Thereafter according to the invention, sothat dilation of the incision can be carried out, the needle-knife wireis removed from the needle-knife conduit and replaced by a guide wire asdescribed in detail above. Then the needle-knife device is removed fromover the guide wire and replaced with a dilating balloon catheter whichis threaded over the guide wire, through the accessory channel of theendoscope, and through the incision. Finally the balloon catheter isinflated to effect the desired dilation of the incision.

As is evident from the foregoing, while the incising and dilating stepscan be accomplished sequentially, with independent instrumentssequentially exchanged and actuated, that process requires the provisionof additional instruments and additional steps which can compromise theefficiency of the procedure and increase the risk of error.

As briefly described above with reference to FIG. 6, according to theinvention, to gain access to the peritoneal cavity via the intestinaltract, a flexible overtube 10 of suitable length is introduced via theesophagus 34, or colorectally, preferably with an endoscope 40 disposedtherewithin to steer and guide the overtube to a target portion of thedigestive tract. Once so located, with the distal end of the overtubeand endoscope in opposed facing relation to the target site forpenetration through the wall of the digestive tract, an incising device,preferably the above-described dilating needle-knife device 42, isadvanced through an accessory channel of the endoscope 40 so as toprotrude beyond the endoscope. The needle-knife 48 is then actuated toprotrude from the distal end of the needle-knife conduit 44 as shown inFIG. 7. The balloon 54 of the dilating device should be fully deflatedbefore introduction through the endoscopic channel. The creation of avacuum in the balloon with a syringe or the like applied to port 56 willthus facilitate insertion. A lubricant may be provided to the balloon 54and outer surface of the device 42 to facilitate conduct to the targetsite through the endoscope 40. A silicone lubricant is preferred in thatregard.

Once the needle-knife device is properly located, the incision line isdetermined and the needle-knife device is elevated using a conventionalelevator associated with the accessory channel, or by displacing theentire distal tip of the endoscope 40, to move the needle-knife up anddown the incision line as shown by arrow C in FIG. 7. Theelectrosurgical unit (not shown) is then actuated so that electriccurrent flows to the needle-knife wire 48 thereby to substantially heatthe needle-knife so that the instrument is ready to incise the stomachwall. Actuation may be effected in any desired manner, for example usinga switch (not shown) provided on the actuator 46, with a foot pedal, orwith another remote actuation device.

The needle-knife 48 is moved along the previously established incisionline to simultaneously cut and cauterize the tissue. Once the incisionhas been completed while applying a continuous motion, theelectrosurgical unit is turned off and the needle-knife 48 is retracted.Once the stomach wall has been incised, and the needle-knife retracted,the needle-knife device 42 is advanced so as to be disposed fullythrough the stomach wall as shown in FIG. 8. Again, the balloon of thedilating device should be fully deflated before introduction through theincision in the stomach wall. The needle-knife dilating device isadvanced until the balloon is positioned essentially in the stricturedefined by the incision through the gastric wall. Radiopaque markers maybe incorporated on the conduit 44 and/or within the balloon 54 as visualmarkers for proper positioning.

The needle-knife actuator 46 with attached needle-knife wire 48 is thenremoved from the needle-knife conduit 44 and a guide wire 58 is fedtherethrough in its stead. Thus, in the unlikely event that theneedle-knife is displaced so as to be removed from the incision in thestomach wall, the incision is located by the guide wire and theneedle-knife device can be readily re-placed to complete its dilatingfunction. Once the guide wire 58 has been fed through the needle-knifeconduit 44 and the needle-knife device is disposed so that the balloontraverses the incision in the stomach wall 36, the balloon 54 isinflated, preferably while monitoring the balloon pressure using, e.g.,a manometer, to effect a suitable dilation of the stomach wall, as shownin FIG. 9, to allow subsequent insertion of the overtube therethrough.Although the balloon 54 of the dilating device can be filled with air,it is preferably selectively filled with liquid. Liquid creates maximumradial pressure in the balloon for a more effective dilation ofstrictures. If desired, the balloon can be filled with a mixture ofwater or saline and contrast for fluoroscopic observation of theprocedure.

Once the dilating function has been achieved the dilating balloon 54 isdeflated by applying suction to the balloon lumen via port 56. Theovertube and endoscope are then advanced. Once the incision and dilatingfunction of the dilating needle-knife have been completed, theneedle-knife device 42 can be removed from the endoscope accessorychannel and other instruments disposed therethrough in connection withdiagnostic and/or therapeutic procedures to be performed within theperitoneal cavity thereafter. Once the overtube has been properlydisposed to traverse the incision in the stomach wall, the balloons 22,24 of the overtube 10 are inflated to anchor the overtube with respectto the gastric wall 36, as described hereinabove. As noted above, theproximal balloon 22 on the overtube conduit 12 may be inflated inadvance of the distal balloon and indeed in advance of displacement ofthe overtube through the dilated incision in the stomach wall.Pre-dilating the proximal balloon 22 ensures that over insertion of theovertube 10 will be avoided (see FIG. 10). Avoiding over insertion isparticularly desirable at this juncture as the peritoneal cavity has yetto be insufflated and thus it is desirable to avoid potential damage orinjury to the structures within the peritoneal cavity that may resultfrom over insertion. Once the overtube is in place, traversing theincision in the stomach wall, the distal balloon 24 is inflated tocomplete the anchoring process, as shown in FIG. 11. Although theballoons of the overtube can be filled with air, they are preferablyselectively filled with liquid. Liquid creates maximum radial pressurein the balloon for a more effective anchoring of the overtube. Ifdesired, the balloon can be filled with a mixture of water or saline andcontrast for fluoroscopic observation of the procedure.

Once the overtube has been suitably anchored with anchoring balloons 22,24, or other anchoring mechanism, the endoscope 40 may be advancedbeyond the distal end of the overtube as shown in FIG. 12 so that thestructures disposed within the peritoneal cavity can be observed, e.g.,for diagnostic purposes. As with conventional endoscopic intra-abdominalprocedures, gas is desirably injected via the endoscope to insufflatethe peritoneal cavity to enable e.g., manipulation of the endoscope anda clear view of the structures of interest within the peritoneal cavity.Additional media can be injected via port 62 in valve housing 14, asdeemed necessary or desirable. Once the endoscope has been thusdisposed, a variety of endoscopic procedures can be carried out in themanner similar to procedures conducted during Laparoscopy. Thus, avariety of diagnostic, therapeutic and/or surgical accessories may befed through the accessory channel(s) 64 of the endoscope, and dissectedtissue and the like removed therethrough. In the even material is toovoluminous to be readily extracted through the accessory channel 64 ofthe endoscope 40, it can be severed and clamped at the end of theendoscope and removed through the larger diameter overtube 10. Theendoscope 40 can then be re-placed for subsequent visualization andprocedures.

As is evident, a variety of surgical procedures can be performed usingthe transgastric approach described herein above. For example,procedures such as biopsy, the lysis of adhesions, the application ofthe ligating clips to fallopian tubes for tubal ligation purposes,providing anastomotic couplings between adjacent segments of intestineor between the stomach and the portion of the intestine to bypass adiseased organ segment, gallbladder removal (which is discussed ingreater detail below), appendectomy, hysterectomy, and/or other organremoval, and similar such surgical procedures. If additional viewing orinstrument delivery is desired beyond that which can be provided thougha single overtube, a second overtube can be fed through the digestivetract, colorectally. Thus, it can be seen that with the peritonealaccess approach disclosed herein above, at least two passages forendoscopes and instruments can be provided so as to accommodatevirtually any micro-surgical procedure within the peritoneal cavity.

Once the intra-abdominal procedure has been completed, the endoscope 40is retracted into the overtube 10 and at least the distal balloon 24 ofthe overtube 10 is deflated by applying suction to the inflation port28. The overtube and endoscope therewithin are then retracted in theillustrated example into the gastric cavity whereupon, if not previouslydeflated, the proximal balloon 22 of the overtube 10 is preferablydeflated as well. At this point, however, an incision 66 in the gastricwall remains and must be closed, preferably with a mechanical fastener,to complete the procedure. In accordance with a preferred embodiment ofthe invention, clip fixing devices 68 are used to close the incision.More specifically, clip fixing device applicators 70 for passage throughthe accessory channel 64 of an endoscope 40 and clip fixing devices 68of various sizes are commercially available. Since clip fixing devices68 are among the most easily manipulated and applied of the currentlyavailable endoscopically applied ligating devices, the use of clipfixing devices 68 to close the incision 66 is presently preferred.However, other mechanical fasteners such as sutures, staples and othercommercially available ligating devices can be applied endoscopically,and/or another incision closing process or procedure can be used asdeemed necessary or desirable to close the incision.

FIG. 13 schematically illustrates the distal end of the endoscope 40with a loaded clip fixing device applicator 70 projecting therebeyond,poised for application to close the incision 66 remaining after removalof the overtube 10 from the gastric wall. The clip fixing device 68includes first and second arms 72 terminating in a tissue grippingstructure 74. To close the incision, the distal end of one clip fixingdevice arm is contacted so as to engage the tissue on one side of theincision 66, as shown in FIG. 14. Then, as shown in FIG. 15, the clipfixing device 68 is manipulated so that the distal end of the other cliparm engages the tissue on the opposite side of the incision 66 so thatthe clip 68 is engaged with tissue on both sides of the incision. Theclip fixing device actuator 70 is then actuated to close the clip fixingdevice 68 and clamp the tissue therebetween so as to close theassociated portion of the incision, as shown in FIG. 16. Depending uponthe size of the incision 66, one or more additional clip fixing devices68 may be applied. In the illustrated embodiment (FIG. 17) a second clipfixing device 68 is applied to securely close the incision.

EXAMPLE

We evaluated the feasibility, efficacy and safety of an endoscopictrans-gastric approach to the peritoneal cavity in a porcine model withlong-term survival. Methods: 45-50 kg pigs had initial endoscopicneedle-knife incisions of the gastric wall followed by balloondilation/electrocautery of incision under general anesthesia usingsterile techniques. Antibiotic irrigation of stomach was performed priorto initial incision for pigs #3, 4, 5. The endoscope underwent highlevel disinfection followed by gas sterilization and was advanced viasterile overtube into the peritoneal cavity for peritoneoscopy and liverbiopsy. The gastric incision was subsequently closed with clip fixingdevices. The pigs were sacrificed at 14 days. Peritoneal cultures,endoscopic and pathologic examinations were performed.

Results: 5 pigs had gastric incisions that were easily performed withrapid access to the peritoneal cavity using a sterile endoscope.Insufflation of the peritoneal cavity was quick and the view of theintra-abdominal organs was spectacular. The intra-abdominal and pelvicorgans were readily seen and accessed for complete examination. Directedliver biopsies were easily performed and closure of gastric incision wassuccessful in all pigs. All pigs were able to tolerate a regular dietwithin 24 hours, eat heartily and thrive over the next 14 days with amean weight gain of 7.1 pounds (±2.6 pounds, 95% C.I. (3.87,10.3).Endoscopic follow-up of the stomach was normal. 4/5 pigs had negativefollow-up cultures. 1/5 pig had Proteus sp. Grossly, 2/5 pigs had normalstomachs, pathologically 2/5 pigs had microabscesses (pigs #1, 2) and1/5 pig had remote inflammation only. None of the pigs that hadantibiotic irrigation of the stomach developed microabscesses.

Conclusion: This study is the first to show that the transgastricendoscopic access of the peritoneal cavity with prolonged survival isfeasible in the porcine model. This suggests that theendoscopic/transgastric approach to the peritoneal cavity may havepotential for a wide range of surgical interventions.

Flexible endoscopic surgery and examination have been described abovewith reference to accessing the peritoneal cavity through the wall ofthe digestive tract for examination and surgical procedures. One suchsurgical procedure is flexible endoscopic cholecystectomy (FEC) whichrefers to the removal of the gall bladder via the digestive tract usingthe flexible endoscope. More particularly, FEC proposes to access theperitoneal cavity via the digestive tract and, in particular, theintestinal wall, in this case rather than the stomach wall for excisionand removal of the gall bladder. The steps involved in this procedurewould include insertion of the endoscope into the intestines, incisionthrough the bowel wall for passage of the endoscope into the peritonealcavity, removal of the gall bladder, closure of the intestinal wallincision and removal of the endoscope.

Since the first cholecystectomy in 1882, the procedure has becomewidespread with over 500,000 performed annually in the United Statesalone. The safety of this procedure has improved with the overallmortality rate decreasing from 6.6.% in 1932 to 1.8% in 1952 and 0.17%in 1989 with a general complication rate around 4.4-4.9%. A majordisadvantage of this procedure is the need for a relatively largeincision of skin, subcutaneous flat tissue, and abdominal wall musclesleading to prolonged healing of the postoperative wound with significantpain and disability. Furthermore, large incisions are associated with anincreased risk of infection and development of postoperative hernias.

Laparoscopic cholecystectomy was reported first in the late 1980s andwas an attractive option because of the smaller incisions used.Initially, it was used only sporadically in few centers in Europebecause of the novelty of this unfamiliar approach to cholecystectomy inthe United States. However, with advances in laparoscopicinstrumentation and the obvious advantages of microsurgical techniqueover open surgery (small skin incision, minimal injury to the tissues,short postoperative hospital stay, etc.), there was widespreadacceptance of laparoscopic cholecystectomy as the ideal technique forcholecystectomy. Although the mortality rate is low 0.07% a majordrawback remains the necessity of entering into peritoneal cavity via atleast 3 separate skin incisions, resulting in postoperative scars,possible infection and postoperative hernias.

We propose FEC as the next step in the development of minimally invasivecholecystectomy. This procedure will consist of upper endoscopy via analready existing natural entrance (mouth), incision of the gastric orintestinal wall to enter the peritoneal cavity, removal of thegallbladder and closure of the incised wall. Thus, FEC will not requireskin incision. This will result in a perfect cosmetic effect, entirelyeliminating the possibility of postoperative hernias. As nerves andmuscles of abdominal wall will not be incised, FEC will be painless.This makes FEC potentially an outpatient procedure.

In the state of Maryland alone, 9993 cholecystectomies were performed in1992. In 1996 the average total charge for an in-hospital laparoscopiccholecystectomy was $13,940 and $15,380 for an open cholecystectomy.Average length of stay for a laparoscopic cholecystectomy was 3.37 daysand was 6.12 days for open cholecystectomy.

Flexible endoscopic cholecystectomy is evidently a less invasiveprocedure than traditional cholecystectomy with a expected reduction inpost-operative morbidity such as abdominal pain. As a minimally invasiveprocedure, flexible endoscopic cholecystectomy (FEC) may theoreticallybe performed on an out-patient basis and at least realize a shortened orno-hospital stay. The reduced hospital stay and less invasivecharacteristics of the procedure would produce a significant cost savingas compared to existing laparoscopic and surgical cholecystectomy.Moreover, the absence of external scars make the procedure cosmeticallyperfect.

The instruments preferably utilized for this procedure include theinstruments described above. More specifically, the instrument proposedfor performing FEC include a flexible peritoneoscope which is actuallythe two-part assembly described above including on the one hand aflexible endoscope 40 with large accessory channel(s) 64 for the passageof micro-surgical devices and an outer sheath or overtube 10 formaintaining sterility of the endoscope and defining a path for theendoscope from outside the patient's oral cavity to and through the wallof the digestive tract.

An endoscopic knife is a further instrument required for theimplementation of this surgical procedure for making an incision in thebowel wall and for assisting in excision of the target tissue, such asthe gallbladder. The endoscopic knife is preferably electro-cautery tominimize bleeding following incision. This instrument may additionallyhave a video chip for additional imaging. Various accessories arefurther provided for the peritoneoscope, such as endoscopic dissectingforceps for dissection and ligation of the cystic artery, veins, andcystic duct; an endoscopic clip applicator other suturing or ligatingdevice to ligate vessels, close tissue planes and close the bowelincision; and grabbing forceps for extraction of the gallbladder and/orother target tissue.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1-29. (canceled)
 30. A dilating needle knife device comprising: anelongated conduit having a passage defined therethrough; a needle-knifewire disposed in said conduit and terminating distally in a needle-knifetip; an actuation device provided adjacent a proximal end of saidconduit and secured to a proximal end of said needle-knife wire, saidactuating device including an actuation mechanism for selectivelyshifting said needle-knife wire relative to said conduit for selectivelyextending said needle-knife tip to a deployed position, projecting froma distal end of said conduit, and retracting said needle-knife tip to asheathed position, within said distal end of said conduit; an inflatableballoon structure one of mounted to and defined on an exterior surfaceof said conduit, adjacent said distal end; and an inflation lumenextending proximally from said balloon to an inflation port adjacentsaid proximal end of said conduit.
 31. A dilating needle-knife device asin claim 30, wherein said actuation device further comprises anelectrical coupler, electrically coupled to said needle-knife wire, forselectively coupling said needle-knife wire to a current source.
 32. Adilating needle-knife device as in claim 30, wherein said actuationdevice is detachably coupled to said proximal end of said conduitwhereby said needle-knife wire is removable from said conduit ondetachment of said actuation device from said conduit.
 33. A dilatingneedle-knife device as in claim 30, wherein said inflatable balloonstructure is elongated such that a length thereof is substantiallygreater than a diameter thereof following inflation.
 34. A dilatingneedle-knife device as in claim 33, wherein said length of said balloonis at least about twice the inflated diameter thereof.
 35. A dilatingneedle-knife device as in claim 34, wherein said length of said balloonis about three-five times the inflated diameter thereof.